Music is the art of expressing thoughts and emotions by synthesizing a beat, a tune, and a harmony according to a predetermined law and format based on notes and noises in the audio frequency band. A beat, referred to as a rhythm, refers to a temporal combination of various long/short notes and dynamics and is the most important element forming the basis of music. A tune, referred to as a melody, is temporal harmony of various high/low notes and long/short notes. Unlike a rhythm, a tune is the expression of music and plays an important role in expressing people's emotions. In addition, a tune, as an element that best represents musical expression and people's emotions, may be a linear connection of notes formed by horizontally combining notes having various pitches and lengths. A harmony is a connection of chords generated when two or more notes sound at the same time. A harmony is a simultaneous (vertical) combination of multiple notes, whereas a melody is a successive (horizontal) and monotonic arrangement of notes having different pitches.
Among terms related to music, chords indicate notes synthesized when two or more notes having different pitches sound simultaneously. Chords are denoted by a root note and intervals of constituent notes. The chords may be differentiated according to the name of a root note and may be twelve in number. In addition, the chords may be differentiated according to constituent notes thereof, in which case the chords are divided into major chords and minor chords according to the length of the third, each of which has the perfect fifth. There are diminish chords that have the diminished fifth and the minor third, and augment chords that have the augmented fifth and the major third. Quartal chords are formed by adding the seventh to triads. Major 7 is formed by adding the major seventh to a major triad, Dominant 7 is formed by adding the minor seventh to a major triad, and Minor 7 is formed by adding the minor seventh to a minor triad. A method of writing chords with the name of a root note and constituent notes (e.g., C, Am, Em, or G7) is being widely used in popular music such as folk songs or pop songs. A harmony denotes a connection of chords in which two or more notes having different pitches sound simultaneously. The harmony serves to add a tone color effect by strengthening a melody and a rhythm in a background thereof. In addition, the harmony imparts greater width, depth, and richness to music.
In a so-called tonal harmony by major and minor keys, a triad in which three notes overlap each other at an interval of the third from a root note (e.g., the first) makes up a fundamental chord. A pitch denotes the highness and lowness of a note and as a frequency increases on the basis of the fundamental frequency, a note becomes higher. The name of a note indicates a pitch thereof. The names of notes are arranged in units of semi-tone in order of A, Bb, B, C, Db, D, Eb, E, F, Gb, G, and Ab. An octave refers to the interval between one note and another note with double its frequency. Notes in octave relationships are perceived as being the same as each other, and a note an octave higher than A is also referred to as A. An octave is written with a number there behind. A4 is a note having a fundamental frequency of 440 Hz, and a note an octave higher than A4 is A5. Another method of representing a pitch is an integer notation. A# and Bb have the same pitch in the equal temperament. The integer notation is a method of representing a pitch with an integer between 0 and 11 in units of semi-tone in order to prevent the repetitive notation. Although having been proposed to mainly analyze/compose atonal music, the integer notation is also used to transmit a Midi Note Number (e.g., a number expressing highness and lowness of a note in Midi data) due to usefulness in computer processing. For example, the Midi Note Number is increased/decreased by 1 at an interval of semi-tone, with a central C (C4) set to 60. The amount of difference in pitch between two notes is referred to as an interval. A particular pitch has no musical meaning. The particular pitch has meaning only as a relationship with other notes, namely, as an interval. There are two musically important methods of determining a standard note of an interval. One is to identify intervals of notes of a musical scale based on a key note, and the other is to identify intervals of chords and melodies based on the standard note of the chords. There is a method of writing an interval in units of Do based on a major scale. In this method, the interval of two notes on the same step in a musical scale is referred to as the first or the same, and the interval of two notes on adjacent different steps is referred to as the second. As the distance is increased by one step, namely, the second again, the interval is sequentially referred to as the third, the fourth, the fifth, the sixth, and the seventh, and the eighth is also referred to as an octave. The type of Do is divided into “perfect,” “major,” and “minor.” When one semi-tone is increased in “perfect” and “major,” it is referred to as “augmented,” and when one semi-tone is decreased in “perfect” and “minor,” it is referred to as “diminished.” When constituent notes of a musical scale are written with intervals, a key note may be the criterion, and when constituent notes of chords are written with intervals, a root note of the chords may be the criterion. The root note of the chords is written with a roman numeral based on the key note. Another method is to use the name of a scale (Movable Do). The name of a scale is used for expressing constituent notes of a musical scale, instead of expressing constituent notes of chords. Tonality refers to a phenomenon that any one note predominates as a central note and other notes are subordinate to the central note (key note). For example, music in a major scale with note C as a key note is referred to as “C major,” in which case the note C is the center of the music and the rest has functionality according to relationships with the note C. Determining a key depends upon a key note, and there are twelve major keys and twelve minor keys in European music. In a musical scale of tonal music, notes are sequentially arranged in order of particular intervals from a key note, and western music is based on a heptatonic scale. Constituent notes of a musical scale are referred to as the name of a scale and are arranged in order of Do, Re, Mi, Fa, Sol, La, Si, Do, Re, etc. A major scale begins with Do, and a minor scale begins with La. Notes between Mi and Fa and between Si and Do are semi-tones, and the rest has intervals of whole tones.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.